Roll bale is another form of stored forage. Grass is cut and baled while it’s still fairly wet. If it is too wet, it can’t be baled and stored the same as hay. Thus, the proper moisture content for roll bale silage making is around 60 to 70%. The bales are wrapped tightly with 6 layers of 0.025-mm thick plastic film on a bale wrapper. The material then goes through a limited fermentation in which short chain fatty acids are produced to protect and preserve the forage. This method has become popular on some farms. In Japan, the roll bale silage preparation method of fresh rice straw was developed (Fig. 5.6.3), and the animal feed production from biomass resources is expected to make the best use of roll bale technology.

— Biodiesel

Severe air pollution over the big cities in Korea also helps the introduction of biodiesel in the transport sector because biodiesel blended fuels may reduce the emissions of the air pollutants from vehicles. Demonstration supply of BD20 had been started in Seoul Metropolitan and Chonbuk Province from May 2002 and lasted by June 2006. During the period of the demonstration supply, several important works have been done to resolve the controversial issues like the feasibility of BD20 as a motor fuel, the preparation of the biodiesel fuel specification and the establishment of distribution infra for the biodiesel blended fuels. After a year work, the draft for the standards having 16 specification parameters was made. The figures taken in the standards are virtually same to those of the European standards, EN14214. Actual fleet tests also have been done with BD5 and BD20 prepared with the biodiesel which meets the Korean biodiesel standards for two years. Through the fleet tests, BD20 was found to be not suitable for the passenger cars. In the meanwhile, no troubles have been observed with the use of BD5. So KMOCIE prepared a new biodiesel distribution system and enforced it from July of 2006 (Figure 1). According to new plan, all Korean oil refineries should buy 100,000 kl biodiesel /year and mix them into their diesel products and supply the blended diesel to all gas stations. As a result, all diesel oils sold in Korea contain about 0.5% of biodiesel. BD20 is allowed to supply only to captive fleets which have their own gas pumps.

With the strong support of Korean Government on biodiesel implementation, the biodiesel business is getting active. The stable supply of raw material is going to be an important issue. Various activities are under way to secure the stable supply of feedstocks for biodiesel production. The activities include the demonstration cultivation of winter rapeseed to determine the feasibility of mass production of canola domestically and Jatropha plantation in some Southeast Asian countries..

In China, the area of small-scale biomethane digester is about 6-8 m2. Annual output is 300 m3. Cost of each biomethane digester is 1500-2000 RMB.

In spite of providing energy, biomethane in China also has the following characteristics: 1) environment friendly. For an 8-10 m3 biomethane digester, dejecta of 5-8 pigs or 2000-3000 chickens can be used. 2) The residues in the digester can also be used for fertilizer. 3) economically. It saves money of buying electricity or save labor of seeking firewood. And the woods can be saved.

8.1.3. Process of small-scale biomethanation

The process of small-scale biomethanation includes feedstock collecting, pretreatment, fermentation, treatment and purifying, storage and transportation, where the fermentation digester is the main equipment. The digesters are required to be airtight and impervious to make sure they are anaerobic. The temperature in the digester should be maintained at 20-40°C. There should be enough manure in the digester. Appropriate water (about 80%) content and pH (7-8.5) are required.

Batch fermentation and semi-continuous fermentation are usual technologies for small-scale biomethanation. In batch fermentation technology, all the feedstock is added at the first. The biomethane generates fast at the beginning and then decreases. This technology is easy for management, but the biomethane generation rates are different. In semi-continuous fermentation technology, 1/4 — 1/2 feedstock was added at the first. When the biomethane generation slows down, more feedstock is added to make the biomethane generation work in order.

There are opportunities for developing countries to get foreign currency by exporting bioenergy. In the case of cassava production in Thailand, for instance, the cassava production for food and that for ethanol are balanced now. However, the future use of cassava should be carefully determined. In the future, the amount of cassava production for ethanol may increase, while it is often said that bioenergy utilization may be in conflict with food production, i. e., the international growing demand for ethanol may threaten the stability of domestic supply of food.

Further information

Asifa, M.; Muneer, T. Energy supply, its demand and security issues for developed and emerging economies, Renewable and Sustainable Energy Reviews, 11, 1388-1413(2007)

Carpentieri, M.; Corti, A.; Lombardi, L. Life cycle assessment (LCA) of an integrated biomass gasification combined cycle (IBGCC) with CO2 removal, Energy Conservation and Management, 46, 1790-1808 (2005)

Saxena, R. C.; Adhikaria, D. K.; Goyal, H. B. Biomass-based energy fuel through biochemical routes: A review, Renewable and Sustainable Energy Reviews (in press)

The Japan Institute of Energy. “Report on the Investigation and Technological Exchange Projects Concerning Sustainable Agriculture and Related Environmental Issues,” Entrusted by the Ministry of Agriculture, Forestry and Fisheries of Japan (Fiscal year of 2006) (2007)

E. crassipescontaining all essential amino acids supplies excellent livestock feed such as pig and chicken although heavy metals absorbed in the plant has to be eliminated for practical applications. For energy uses, 373 m3/tonFW bio-gas containing 60-80% methane and ca. 5,300 kcal/m3 for burning calorie was obtained by anoxic fermentation of E. crassipes. Since E. crassipes contains 3.2% of nitrogen, 0.7% of phosphorus and 2.8% of potassium in total DW, applications for fertilizer and soil amendment agent are now under considered.

Eeel-grass biomass is used as a part of feed of sea pig and manatee in aquaria. Technology of artificial cultivation of eel-grass has not been established yet.

Seaweed biomass has been widely used in the world (Table 2.10.1). Yearly harvesting of attractive seaweeds is ca. 1.3 M (million) tonsFW for brown algae and ca. 0.81 M tonsFW for red algae. Most of them are natural, and artificial cultivation has increased recently. Seaweeds have been used for dried feed, human food, fertilizers, soil amendment agent and so on. Useful materials contained in seaweeds such as unique polysaccharides, iodine and so on are used for raw materials for extracting the useful substances (Indergaard, 1982). Kelp contains alginic acid in 13-45% of DW which is used for producing foods, medicines, cosmetics, dyes, paints, paper manufacturing, interior finishing materials, lubricating oil and so on. Some red algae contain agar and agar-like carrageenan.

Micro-algae contain high percentages of protein reaching 50-70% of DW. Various utilizations of health care supplements, raw materials for extracting pigments such as carotenoids and phycobilins, and vitamins, and feed for aquatic organism are now in business for micro-algae. Due to micro-size and low biomass concentrations in natural, micro-algal biomass is prepared by artificial cultivation in tank, pool or channel on land in low or middle latitudes suitable for year round cultivation. A business model has been proposed to culture filter feeder sea shells fed micro-algae cultured by nutrient rich deep seawater (Roels et al., 1979).

3.3.1 Particleboard

Composition board has many names and definitions. Particleboard is a general term for a panel manufactured from lignocellulosic materials (usually wood), primarily in the form of discrete pieces or particles, as distinguished from fibers, combined with synthetic resin or other suitable binder. The particles are bonded together under heat and pressure in a hot press by a process in which the entire interparticle bond is created by the added binder; other materials may be added during manufacture to improve certain properties (ASTM D 1554). Classification of particleboard varies, depending on country. For example, Japanese Industrial Standard (JIS) A 5908 classifies particleboard into five categories on the basis of: 1) surface condition, 2) bending strength, 3) adhesive, 4) formaldehyde release amount, and 5) flame resistance. Fiberboard is a general term for a panel manufactured from lignocellulosic fiber. This chapter does not cover fiberboard.

Products made from comminuted woody materials in the shape of fiber, shavings, and particles can be made from woodworking waste, noncommercial or low-value wood, and agriculture waste. Bark, forest slash, and industrial waste can be included in the products. The manufacture of composition board is a conversion of previously unused natural resources to useful products. Thus, particleboard production is considered a technology for recycling woody cellulosic biomass resources for sustainable forestry.

Biomethanation is commercialized for food waste, cattle waste, sewage sludge, and wastewater. European countries have developed biomethanation technology. Biogas plants have been gradually increasing in Japan. The reaction takes place at high, moderate, or low fermentation temperature, and organic content classifies biomethanation into wet and dry fermentation. High temperature systems reveal high gasification performance compared with other temperatures. Disadvantageous points of biomethanation are low digestion ratio, low removal ratios of ammonium and phosphate, long treatment time, and necessity of heat. Fermented effluent and residue should be recycled for agriculture as an organic fertilizer since treatment cost is high. Technological developments is being conducted to overcome these issues.

Further information

Ahring, B. K., “Biomethanation I”, Springer, (2003)

Nagai, S.; Ueki, K., “Anaerobic microbiology”, Youkenndou, (1993) (in Japanese) Speece, R. E., “Anaerobic biotechnology for industrial wastewaters”, Archae Pr, (1996)

Energy consumptions to produce 1 MJ energy were compared between biomass and fossil fuel (coal) (Table 6.2.6). For both cases, the transportation stages from production site to utilization site are omitted for simplification.

Fig. 6.2.2 shows energy consumption and CO2 emission of biomass and fossil fuel respectively, then the part of ®+® and ®’+®’ indicate the boundary here. In the case of biomass, ®+® means energy consumption for the stage of afforestation, crushing, and drying. Coal mining data were obtained from the data of Australia.

Fig. 6.2.3 shows the results of comparison. Energy consumptions of biomass production in North America, Indonesia and Brazil are 0.182 MJ/MJ-biomass, 0.200 MJ/MJ-biomass and 0.132 MJ/MJ-biomass, respectively, and energy consumption of coal production is 0.008 MJ/MJ — coal. The result shows that biomass production process requires much larger energy than coal production process in order to obtain equivalent energy.

On the LCA, energy consumption evaluation target is determined based on the use of exhaustible energy resources. So biomass energy consumption is not counted as energy

consumption, if the biomass is obtained from sustainable afforestation. In addition to this energy consumption for production, 1 MJ of exhaustible energy resource is consumed at energy usage stage for coal. As a result, life cycle energy consumption becomes lower for biomass than for fossil fuel.

Fig. 6.2.2. Energy Consumption and CO2 Emisssion image on Biomass and Fossil Fuel.

Fig. 6.2.3. Comparison Between Biomass and Coal on Energy Consumption and CO2

Further information

Turhollow, A. F. and R. D. Perlack, Biomass and Bioenergy, 1(3), pp.129-135, 1991

NEDO, “Investigation of forest from a viewpoint of global environment (the 2nd) (a case study of planting)”, NEDO-GET-9603, 1996 (in Japanese)

Yokoyama, S., “Eucalyptus Plantation in Brazil, Resources and Environment”, Shigen to Kankyo, pp.431-436, 1996 (in Japanese)

IEEJ (Institute of Energy and Economics in Japan), “Life Cycle Inventory Analysis of Fossil Energies in Japan, IEEJ, 1999 (in Japanese)

In Malaysia, biomass resources are mainly from the palm oil, wood and agro-industries. All of these residues come in many forms such as palm oil mill residues, bagasse, rice husks and wood/forest residues. Major sources of biomass come from the oil palm residues in the form of empty fruit bunches (EFB), fibers, shells, palm trunks, fronds and palm oil mill effluent (POME). The energy content in each residue is different to each other. This is mainly because the caloric value, moisture content and some other parameters that are different.

As shown in table below, the palm oil residues accounts for the largest biomass waste production in the country. This is because the palm oil mill residues are easily available and are presently requiring cost effective means of disposal. Currently, most of these residues are disposed of through incineration and dumping. A small portion is used as fuel for the mills’ heat and power requirement in a very inefficient manner.

Since lignocellulose is mainly composed of cellulose, hemicellulose and lignin, it needs additional pretreatment in order to get sugar monomer ready for the fermentation process.

Typical process requires SHF (Separate Hydrolysis and Fermentation) of great complexity involving pretreatment, fractionation, delignification, hydrolysis and fermentation. Alternatively, pretreatment with proper steam explosion yields the hydrolysate, which can be enzymatically digested and fermented in a single reactor via SSF (Simultaneous Saccharification and Fermentation) method, as shown in Fig. 8.5.3, 8.5.4 and 8.5.5, involving only the pretreatment and hydrolysis/fermentation steps. The goal is to seek for the appropriate SSF that uses a commercially available cellulase enzyme and microorganism available in Thai market.

Source: C. Pomchaitaward et al, MTEC report (2007)

The steam explosion was applied to rice straw Supunburi1™ showing good carbohydrate recovery and high ethanol concentrations obtained in a single reactor with minimal enzyme and yeast supplementation. A 150 g of dried rice straw was steamed with pressure between 10 to 25 bar (with corresponding temperature 185 and 210 °С, respectively) for 5 minutes. Higher

steam pressure (or higher temperature) favored hemicelluloses solubilization. However, the

strong influence of steam pressure on the cellulose solubilization was not found.

pretreatment condition resulted in the production of a very small amount of sugar decomposition products, which enabled an effective fermentation of sugars to ethanol. In conclusion, mild steam pretreatment condition at 15 bars for 5 minutes results the highest hydrolysis yield.

This process substantially reduces the complexity of the overall rice straw to ethanol bioconversion, while simultaneously lowering the capital investment cost and time associated with the need for separate processes. Furthermore, it significantly lowers environmental impact due to less hazardous process chemicals and conditions involved. Last but not least, it provides an alternative for better energy efficiency in agricultural residue management.

Further information

C. Pomchaitaward et al, Feasibility Study of Ethanol Production from Lignocellulosic Materials via the Steam Explosion Pretreatment, MTEC in-house project report 2007 (chaiyapp@mtec. or. th)

S. Nivitchanyong, Alternative Energy Cluster, MTEC (siriluck@mtec. or. th)