4.1.2.1 Hydrogen by Pyrolysis of Biomass

Pyrolysis is a conventional process to heat and thermally decompose the biomass at high temperatures of 650-800 K under 0.1-0.5 MPa in the absence of air to convert biomass into liquid oils, solid charcoal and gaseous compounds. Pyrolysis is one of thermolysis and is commonly used for charring of organic materials. In general, pyrolysis of organic substances produces gas and liquid products and leaves char as a solid residue rich in carbon. Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization. Pyrolysis can be classified into fast pyrolysis (Baumlin et al. 2006; Su-ping Zhang et al. 2011) and slow pyrolysis (Karaosmanoglu et al. 1999; Phan et al. 2008). The fast pyrolysis is a high temperature process, in which the biomass is heated rapidly in the absence of air and vapor is formed and subsequently condensed to a dark brown mobile bio-liquid.

Hydrogen can be produced directly through fast or flash pyrolysis when the pyrolysis condition of high temperature, sufficient volatile phase, and enough reac­tion time are attained:

Biomass ^ heat ^ H2 + CO + CH4 + other products. (4.1)

Methane and other hydrocarbon vapors can produce more hydrogen via steam reforming:

CH4 + H2O ^ CO + 3H2. (4.2)

Hydrogen can be produced by the following water-gas shift reaction:

CO + H2O ^ CO2 + H2. (4.3)

However, the slow pyrolysis is normally not considered for hydrogen production because the products are mainly charcoal.

Therefore, the ultimate objective of this project is to enable development of superior methods for the production of bioethanol-used appropriate feedstock like oil palm. The specific target is the ethanol industry, where replacement of fermentation with appropriate reactions for propulsion is urgently required to bring about a substantial reduction in greenhouse gas emissions to the environment. To achieve this, our spe­cific aims are to:

1. Estimate the amount of biofuels/ethanol that can be reasonably produced using the lignocellulosic resources available in Malaysia. Suggestions will be made on the potential scale-up of biofuel production.

2. Develop physical and chemical methods that enable direct measurement of etha­nol production-used EFB.

3. Evaluate our method that influences catalyst, temperature, and other factors on saccharification and fermentation.

10.4.2.1 Solid Acid Catalyst

Yee et al. (2011) tested the catalytic activity of acid solid catalyst (sulfated zirconia supported with alumina) for the transesterification of Jatropha oil with methanol. Under optimum condition, 78.2% of biodiesel was yielded at 150°C, 3 h reaction time, methanol/oil molar ratio of 8 and catalyst amount of 8 wt%. The results revealed that calcination temperature and calcination duration significantly affected the transesterification activity of the catalyst. The optimum catalyst calcination tem­perature and duration was 490°C and 4 h, respectively, with more prominent tetrag­onal crystalline phase of zirconia and higher specific surface area. Further increment of temperature above 500°C resulted decrement of biodiesel yield. This was due to collapse of catalyst surface area and decomposition of sulfated group resulting the absence of S=O bond.

Guo et al. (2011) studied on catalytic efficiency of commercial ionic liquids in both esterification and transesterification reaction of high acid value Jatropha oil (13.8 mg KOH/g). The commercial ionic liquid 1-butyl-3-methylimidazolium tosylate [BMIm][CH3SO3] gave high esterification activity (93%) at 140°C but only 12% biodiesel yield at 120°C. This result indicated that ionic liquid consisted of Bronsted acid sites that favor the esterification reaction. When the metal chlorides (FeCl3) were loaded with [BMIm][CH3SO3], both esterification and transesterifica­tion activities were very high with 97% FFA conversion and 99.7% of biodiesel yield. This was due to the presence of trivalent metallic ions in the [BMIm] [CH3SO3]-FeCl3 which created Lewis acidic sites that promote reactions.

Zanette et al. (2011) investigated the catalytic activity of a variety of solid cata­lysts (resins, zeolites, clays, hydrotalcites, aluminas, and niobium) in the trans­esterification of Jatropha oil with methanol. The catalyst screenings were conducted under operating conditions of 120°C, 5 wt% catalyst loading, metha — nol/oil ratio of 9:1 for 6 h reaction. The results revealed that KSF clay and Amberlyst 15 resins catalyst gave the highest activity as compared to other type of catalysts (<20% of biodiesel yield). A central composite rotatable design (CCRD) was carried out using KSF and Amberlyst 15 as catalysts. Reaction with KSF clay and Amberlyst 15 was then performed at optimum condition of 160°C with metha­nol/oil ratio of 12:1, 5 wt% catalyst amount for 6 h in order to improve the bio­diesel yield to about 70%.

Experiments were performed to examine the effect of temperature on the catalytic activity of immobilized lipase in the transesterification of crude J. curcas oil with ethanol. Temperatures in the range of 35-55°C at constant ethanol concentration were studied, and the results are shown in Fig. 12.7d. The optimum temperature was found to be 35°C. As reaction temperature was further increased, a decrease in ethyl ester formation was noticed. Thus, biodiesel productions at low temperatures are an added advantage over chemical catalysts because energy could be saved and also is environmental friendly.

The oil palm biomass (mesocarp fibre, palm shell and EFB) is currently used to fire boiler to produce steam and electricity for combined heat and power production. Hence, palm oil mills are so far self-sufficient in energy.

Before oil palm biomass can be used as a solid fuel, it has to be physically treated. EFB requires physical pretreatment to reduce size and moisture content to enable it to behave more efficiently as a fuel. EFB in fibrous form can be more efficiently utilised as a feedstock for various conversions into second-generation biofuel.

Through briquetting (Nasrin et al. 2011) and pelletising, oil palm biomass in loose form is compressed/compacted into higher density fuels via mechanical treat­ment for easy handling, transportation and storage of materials as solid fuel or to generate energy via gasification or for export market. It can be further treated into charcoal or torrefied pellet/briquette.

To date, there are four grid-connected biomass energy plants in Malaysia (Ministry of Energy, Green Technology and Water 2011), each utilising approxi­mately up to 300,000 tonnes of EFB per year for electricity generation.

The palm oil roots (OPRs) have the fibrous (or adventitious) root system which comprises numerous, tiny moderately branched nonwoody roots growing from the base of the OPT. The primary roots of the OPR system are of constant diameter and emerge independently and periodically from an area at or near the base of the OPT called the root initiation zone (Dransfield et al. 2008). OPRs are usually isolated from the palm tree during replanting by using an excavator or a stump grinder. The OPR forms about 12% the total mass of the OPT at full maturity. Normally, OPTs are not felled together with the root system; hence, OPRs have not gained much attention for value-added products. However, the chemical characteristics of OPR show the presence of high amount of sugar or carbohydrate close to that of OPF with higher contents of extractives.

Catalysts play an important role in conversion of lipid and triglycerides into bio­diesel. They also hold the key to the overall profitability of biodiesel production. A catalyst functions by speeding up a chemical reaction and is not permanently changed or consumed. Employing catalyst for the transesterification step should enable the reaction to proceed at moderate operating conditions with high biodiesel yield. Different types of catalysts are being studied for efficient biodiesel synthesis, and each of them has their own strengths and weaknesses.

Biodiesel can be produced from a variety of feedstock including vegetable oils, animal fats, and waste cooking oils. At present, most commonly used feedstock for production of biodiesel are edible oils such as soybean, rapeseed, canola, sunflower, palm, coconut, and corn oil. In general, the choice of biodiesel feedstock depends mainly on its geographical distribution: for example, soybeans for the United States, rapeseed sunflower oils for Europe, palm oil for Southeast Asia, and Jatropha oil for India. The practice of using edible oils for biodiesel production has raised the con­cern of food versus fuel issue. Critics from different parts of the world raise issue that the edible oils when used as biodiesel feedstock compete with the food indus­try. Also developing countries having insufficient edible oils for food find it impos­sible to produce biodiesel. For example, 9.3% of world’s total oil seed production is done by India and is considered to be one of the promising edible oil producing countries. Even then, 46% of edible oils are imported just to meet the human con­sumption. China’s situation is also more or less the same; the country needs to import 400 million tons of edible oil annually to meet the population demand. Thus, in such situations, nonedible oils play an important role as biodiesel feedstock (Jain and Sharma 2010; Lu et al. 2009; Al-Zuhair 2007; Makkar et al. 1997). Table 12.1 shows the oil content and yield of nonedible oil seeds.

Shah and Gupta (2007) have put forward the significance of J. curcas L. oil for biodiesel production. Due to the presence of curcin, phorbol esters, and some anti-nutritional factors, the oil of J. curcas L. has been rendered unsafe for cook­ing purposes. This fact makes the oil attractive as nonedible vegetable oil feed­stock in oleochemical industries such as for biodiesel production, fatty acids, soap, surfactants, and detergents. Jatropha is also rich in hydrocarbon sources. Approximately 46-58% of semidry oil can be obtained from the kernels of J. curcas L. and contains mainly oleic acid as its composition. Linolenic acid is the main component in other Jatropha varieties.

Gas chromatography analysis was conducted to prove the existence of ethanol in the fermentation samples. Examination of the GC chromatograms for pure ethanol showed a peak at 1.87 (±0.02) min (Fig. 13.11). And the peak appears for all samples (Figs. 13.12-13.15). As this peak appeared in all samples and standard, its presence proved the presence of ethanol in the sample.

The appearance of noisy peak besides the ethanol peak may be due to the pres­ence of trace water and impurities. On the у-axis, there are the values to show the abundance of ethanol in the sample. The highest abundance of ethanol was 500,000

(0.1 M, 100%), followed by 390,000 (0.1 M, 30%), 350,000 (0.4 M, 30%) and 225,000 (0.4 M, 100%) (Figs. 13.12-13.15). The trend of results matches well with the estimation of alcohol percentage at Fig. 13.7.

It was observed that there were peaks at time 1.80 min (±0.02) for some samples (Figs. 13.13 and 13.14). It was the solvent peak for acetone. The solvent peak was present because the injection pin was washed with solvent acetone every time before and after the sample injection into GC column. In Figs. 13.12 and 13.15, there was no presence of acetone because there was no preinjection or postinjection solvent wash to the injection pin.

However, it was also observed that some of the samples have peak at time 1.92 min (Figs. 13.11 and 13.13). As there was no way to identify the real compo­nent at this peak with a GC, it can be any of the fermentation products such as glycerol or succinate or trace water peak.

13.2 Conclusion

Bioethanol is a potential alternative fuel, but it is also important to make sure that the expansion of this fuel will not be restricted by the raw material. The demand for land use is becoming more of an issue because it raises the competition for land between energy crops and food. By considering marine biomass like seaweeds, the issue can be resolved.

This study had successfully investigated the feasibility of fermenting E. cottonii using S. cerevisiae. The effect of extraction and acid hydrolysis on the release of sugar content was identified by phenol-sulphuric method. The data show that high molarity (0.4 M) and high temperature (100%) of acid hydrolysis give higher sugar concentration in the hydrolysate. However, the ethanol concentration does not agree with the amount of reducing sugar results. The highest ethanol production was achieved with 0.1 M, 100% acid hydrolysis, with 8.41% v/v. 0.1 M acid meant that

a lower concentration of acid was preferred. It may mean that the hydrolysis reduced the carbohydrates into simple sugars which were not fermentable by S. cerevisiae.

From the results of ethanol percentage, it proved that the extracted seaweed gives higher percentage of ethanol (9.58% v/v) compared to non-extracted seaweed (3.33% v/v). With extraction, carbohydrates that formerly entrapped in the seaweed were released and readily available for hydrolysis and subsequently for yeast to digest. Therefore, carbohydrate extraction was proposed as the necessary pretreat­ment to release and convert complex carbohydrates into simple sugars to produce higher ethanol percentage in the fermentation media.

Besides that, among the three fermentation media, it was found that Yeast Peptone Dextrose (YPD) broth yields the highest percentage of ethanol (9.58% v/v) followed by Yeast Extract Peptone (YP) broth producing 4.70% v/v ethanol. E. cot — tonii slurry yielded 1.27% v/v ethanol.

Yeast Peptone Dextrose (YPD) provides complete medium and supplements such as yeast extract, peptone and dextrose for rapid growth of yeast, and as a result,

produces higher ethanol percentage. However, the introduction of glucose/dextrose in the YPD broth affects the utilisation of the targeted carbohydrate and sugar from seaweed as the source for the ethanol fermentation. This is because the carbon source for fermentation might come from both sugar in seaweed and added glucose in YPD broth. As a conclusion, YPD broth increased the rate of yeast growth to produce more ethanol. At the same time, it also increased the sugar concentration in fermentation broth thus producing highest ethanol.

On the other hand, Yeast Extract Peptone (YP) broth could be used as the fermentation medium as only targeted carbohydrate and sugar from seaweed can be utilised by the yeast and turn it into ethanol. It produced the second highest ethanol concentration.

The results from this study confirm that red macroalgae, E. cottonii, have a potential to be used as a substrate for bioethanol production but may be a challenge for large-scale commercial production as without addition of growth-promoting fermentation media the alcohol production was low.

Acknowledgments We would like to thank Universiti Malaysia Sabah and School of Engineering and IT for the research facilities. We would like to acknowledge Borneo Marine Research Institute and Institute for Tropical Biology and Conservation for their provision of raw material and chemicals.

As at May 2012, POIC Lahad Datu has attracted a total of 42 investments on 465.9 acres of land with a total investment value of RM4.5 billion. The nature of business of the companies invested at POIC Lahad Datu includes fertilizer production, refin­ery, oleochemicals, palm kernel crushing/expelling, storage, warehousing and logis­tics, small renewable energy power plant, bulking installation, spent bleach earth extraction and waste treatment, palm fiber and pelletization, processing and packag­ing of palm products, palm-oil-related activities, manufacturing of packaging prod­ucts, oil and gas, and other supporting activities.