Furfural and Bioethanol Production from Hardwood and Agricultural Waste

In the near future hardwood may be a real alternative to oil as a raw material for production of chemicals and motor fuel. A new approach to solve this problem has been found. The aimed change of the mechanism of the process has permitted to solve two problems simultaneously: to increase the furfural yield from 55% up to 75% from the theoretical yield And to diminish 7 times the degree of cellulose destruction. On the basis of theoretical studies, a new technology including two-step hydrolysis of hardwood and other pentosan-containing raw material has been developed. Since 1997, for the first time in the world's industrial practice, this technology of yielding furfural and bioethanol has been realized in Russia with the annualy capacity of 4.300 t furfural and 11 million l bioethanol. The degree of raw material utilization has grown 3 times compared to furfural production alone

Bioetanola un furfurola kopēja iegūšana no lapkoku koksnes

Naftas cenu celšanos pasaules tirgū pēdējos gados sadārdzināja sintētiskās ķīmijas produkciju un attiecīgi pacēla konkurētspēju produktiem, kurus var iegūt no augu biomasas, tajā skaitā arī etanolu un furfurolu. Pasaulē bioetanola ražošana ik gadus palielinās par 10%. Tagad etanolu ražo, galvenokārt, sintētiski vai arī fermentējot. Bet jau tuvākajā nākotnē, sakarā ar jaunu situāciju naftas tirgū, palielināsies furfurola un bioetanola kopēja ražošana, izmantojot hidrolīzes tehnoloģiju. Tāpēc visi pētījumi šajā virzienā paliek arvien aktuālāk, tajā skaitā arī furfurola un bioetanola iegūšana no lapkoku koksnes, jo šī izejviela ik gadu rodas pasaulē lielā daudzumā. Šinī darbā mums ir izpētīta furfurola veidošanās dinamika un kinētika no bērza koksnes atliekām, saglabājot celulozi tālākai pārstrādei – bioetanola iegūšanai. Iegūtie rezultāti var būt izmantoti furfurola un bioetanola iegūšanas jaunas tehnoloģijas izstrādāšanai

Deacetylation of Alder Wood Hemicelluloses Depending on the Catalyst Amount

The world’s consumption of acetic acid has increased from 6.7 million t in 2002 up to 7.9 million t in 2007 and continues to grow. Besides, the production technology of this product has changed dramatically. Some years ago, when the oil price was lower, acetic acid was produced from ethanol by way of fermentation. Still now 75% of commercially used acetic acid is produced from methanol by the catalytic process. Acetic acid is currently produced by 165 companies, and its major quantity is used for producing vinyl acetate monomer. In connection with the oil price increase, it can be forecasted that it will be necessary to produce acetic acid as well as other chemical products from biomass. Therefore, our studies in this direction become increasingly urgent. To develop the theoretical foundations for the new technology, it is necessary to investigate the effect of the main parameters on the wood hemicelluloses deacetylation process. In the present work, the effect of the catalyst amount on the alder wood hemicelluloses polysaccharides deacetylation process is investigated. The studies were carried out, treating the raw material in the presence of a catalyst with steam in an original pilot plant, with the main reactor’s volume 13,7 l and height 1450 mm. This pilot plant makes it possible to model an industrial process. Kinetic studies have shown that the alder wood hemicelluloses polysaccharides deacetylation reaction rate constant has decreased during the process. For example, at the temperature 430 K and the catalyst amount 1.0% from dry wood, the hemicelluloses deacetylation reaction rate constant has decreased from 2.14 • 10-2 min-1 to 1.41 • 10-2 min-1 during the process. This is explained by the fact that the acetyl groups in the hemicellulose polysaccharide macromolecule are linked variously and unevenly. The acetic acid yield from alder wood, with increasing catalyst amount from 1.0% to 2.0% from dry wood, grows from 57.0% to 80.2% from the theoretically possible one, respectively. To increase this yield still more, it is envisaged to study the effect of temperature on the hemicelluloses polysaccharides deacetylation process

Influence of the Catalyst Amount on the Kinetics of Acetic Acid Formation from Wheat Straw

The growth of petroleum prices on the world’s market within the recent years has raised the cost of synthetic chemical products and, respectively, has enhanced the competitiveness of the products, including also acetic acid, which can be obtained from plant biomass. Acetic acid is currently produced mainly by way of fermentation of alcohol-containing solutions, and only a small part is obtained from wood dry distillation products. However, already in the immediate future, owing to the new state of the art in the petroleum market, the overall production of furfural and acetic acid applying the hydrolysis technology, will grow. Therefore, all studies along these lines, including also acetic acid formation from straw, become increasingly urgent, since this raw material is formed in great quantities worldwide, and it has not yet found regular utilization. In the present work, the kinetics of the formation of acetic acid from wheat straw was investigated. The obtained data can be used to develop a new technology for obtaining acetic acid

Bioethanol Production from Hardwood and Agricultural Waste

In the near future foliage wood may be as a real alternative to oil as raw material for production of chemicals and motor fuel. A new approach to solve this problem consisting of differential catalysis of hydrolysis and dehydration reactions has been found. The aimed change of the mechanism of the process has permitted to solve two problems simultaneously: to make increase the furfural yield from 55% up to 75% from theoretical and to diminish 5 times degree of the cellulose destruction. On the basis of theoretical studies a new technology including two-step hydrolysis of foliage wood and other pentosan containing raw material has been elaborated. Since 1997 for the first time in the world's industrial practice this technology yielding furfural and fermentable sugars further processed into bioethanol has been realized in Russia with capacity 4.300 t/a of furfural and 8.800 t/a of bioethanol. The degree of raw material utilization has grown 3 times, the total yield of furfural and fermentable sugars - 4 times when compared to the only furfural production

Etiķskābes iegūšana no bērza koka koksnes pie tās kompleksas pārstrādes

Tehnisko etiķskābi pasaulē ražo 165 kompānijas 8,2 milj. t gadā praktiski tikai no naftas produktiem. Prognozē, ka tās ražošanas apjoms līdz 2015. gadam palielināsies līdz 11,8 milj. t gadā un to papildus daudzumu vajadzēs ražot, galvenokārt, no biomasas. Pēc Valsts meža dienesta Meža departamenta datiem bērza koksne resursi Latvijā sastāda vairāk nekā 150 milj. m3. Pēc kopējās krājas bērzs aizņem otro vietu starp valdošajām koku sugām Latvijā. Tāpēc ir ļoti svarīgi atrast šiem resursiem ekonomiski izdevīgu izmantošanu. Šīs problēmas efektīvākais risinājums varētu būt kompleksa bērza koksne pārstrāde ražojot etiķskābi un citus produktus. Pārstrādājot tikai 1 milj. m3 šīs koksnes atliekas varētu saražot 25 000 t etiķskābes. Tas dos iespēju ekoloģiski tīri un ekonomiski efektīvi pārstrādāt bērza koksnes atliekas. Lai atrisinātu šo problēmu, pirmo reizi pasaules zinātniskajā praksē, izmantojot jaunā patentā [1, 2] aprakstītās idejas, izpētīta bērza koksnes hemiceluložu polisaharīdu deacetilēšanās un etiķskābes veidošanās procesa galvenās likumsakarības. Parādīts, ka etiķskābes veidošanās dinamiku un iznākumu ietekmē galvenokārt procesa temperatūra, katalizatora koncentrācija un procesa ilgums. Iegūtie rezultāti būs par pamatu jaunai etiķskābes iegūšanas no bērza koka koksnes tehnoloģijai, par kuras rūpniecisko realizēšanu jau interesējas SIA „LFK” un citas firmas Latvijā

The Effect of Catalyst Amount on the Production of Furfural and Acetic Acid from Birch Wood in the Biomass Pretreatment Process

The conversion of lignocellulosic biomass to bioethanol has attracted renewed attention in recent years due to its environmental, economic, and strategic advantages. Birch woodchips were used as the raw material due its several characteristics, such as high cellulose and hemicellulose content that can be readily hydrolyzed into fermentable sugars. Dilute acid hydrolysis was used as the pretreatment process which can be considered as one of the most promising biomass pretreatment methods. But there occur several challenges and limitations in the process of converting birch wood to bioethanol. During the biomass pretreatment process the degradation products such as furfural and acetic acid, which has an inhibitory effect on the further fermentation process in the bioethanol production section, may be form from hemicelluloses. But both these inhibitors as individual chemicals are very important for the production of many products. In order to develop the theoretical foundations for joint production technology of furfural, acetic acid and bioethanol, it is necessary to study the effect of the amount of catalyst on the formation of furfural and acetic acid from birch woodchips and the content of cellulose in the lignocellulose residue after pretreatment process. The effect of the amount of the catalyst on the furfural and acetic acid formation process was studied in a range from 1.5% to 4.0%, calculated on oven dried wood (o.d.w.), while temperature and time of the pretreatment process were constant. The obtained results demonstrated that the effect of the amount of the catalyst on the formation of furfural and acetic acid and the content of cellulose in the lignocellulosic leftover is very significant. The amount of furfural increased from 6.2 % to 10.8%, calculated on o.d.w., the amount of acetic acid increased from 5.2% to 5.8%, calculated on o.d.w., but the content of cellulose in the lignocellulosic leftover decreased from 34.7% to 14.1%, calculated on o.d.w. after 90 min from the beginning of the birch wood pretreatment process

A Preliminary Study of Biorefinery Concept to Obtain Furfural and Binder-Less Panels from Hemp (Cannabis Sativa L.) Shives

The study is related to the development of a biorefinery concept to obtain furfural from hemp shives with Al2(SO4)3 as catalyst in the pretreatment process and binder-less panels from leftover without additional adhesives. Pretreatment temperatures were 160-180°C and time 90 min. The results show that it is possible obtain furfural 64.8-67.2%, calculated from the theoretically possible, and to obtain binder-less panels from pretreated hemp shives, but it is necessary to diminish the moisture content and severity factor of lignocellulose before the pressing stage

Lignocellulose-Based Granulated Activated Carbons Bound with Water-Soluble Carbohydrates

High-density adsorbents are required since only a certain volume of the adsorbent can be packed into adsorption facilities. Some chemical and physical properties of deciduous wood lignocellulose concede a possibility to use this by-product as a raw material for preparation of high-density granular sorbents. Lignocellulose is a by-product of furfural production by a direct method, developed at the Latvian State Institute of Wood Chemistry. It is only partially used as a fuel in boiler-houses for the technological process heat energy self-provision. The lignocellulose of the direct furfural production process contains approximately 25% of water-soluble matter, namely, reducing substances (sugars), water-soluble oligosaccharides, non-volatile acids (mainly levulinic acid), sulphuric acid, the soluble part of ash, etc., acting as binders of granules. The excellent self-binding properties of the lignocellulose become apparent, in particular, after carbonization and activation of granules