The effect of alkaline pretreatment on the thermal decomposition of hemp

The goal of this work was to study the effect of alkaline pretreatments on the thermal decomposition and composition of industrial hemp (Cannabis sativa L.) samples. Thermogravimetric/mass spectrometric measurements (TG/MS) have been performed, on untreated, hot water washed and alkali treated hemp samples. The main differences between the thermal decomposition of the samples are interpreted in terms of the different alkali ion contents which have been determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) method. Principal Component Analysis (PCA) has been used to find statistical correlations between the data. Correlations have been obtained between the parameters of the thermal decomposition and the alkali ion content as well as the altered chemical structure of the samples. The differences in the thermal behaviour of the samples are explained by the different K+ and Na+ content and the changed structure of the hemicellulose component of the samples due to the pretreatments. The more alkali ions remain in the hemp samples after the alkali treatment, the more ash, char and lower molecular products are formed during thermal decomposition

Fenntartható fejlődés és fogyasztás tiszta technológiákkal valamint megújuló nyersanyagokkal és energiákkal = Sustainable development and consumption with clean technologies and renewable raw materials and energies

A 3 téma: 1. Membrános műveletek környezetvédelmi céllal i) pervaporáció (pvap) és membránszűrés (msz) kísérleti és elméleti kutatása ii) metodologia kidolgozása biner és terner elegyek pvap-jának modellezésére iii) pvap.-on alapuló új hibrid eljárás ipari oldószer-visszanyerésére iv) msz.-re bemutattuk széleskörűen alkalmazhatóságát v) megállapítottuk a kétlépéses msz.-i technikák alkalmazhatósági előnyeit vi) a msz sikeres modellezése. 2. Szilárd anyagok szuperkritikus fluid extrakciójának vizsgálata, és az anyagátadás modellezése i) több növény félüzemi méretű extrakciója szuperkritikus szén-dioxiddal ii) a művelet leírására egy egyszerűsített és egy összetettebb modellt alkalmazva megállapítottuk a mintaelőkészítés, az extrakciós- és szeparációs körülmények paraméterekre gyakorolt hatását iii) a Sovava modell fejlesztése, iv) a különböző extrakciókkal kapott termékek összehasonlítása. 3. Cellulázok és kísérő enzimek hatásának kísérletes és matematikai tanulmányozása A hazai agro lignocellulóz (lc) technológiai potenciáljának, és az etanolgyártás szempontjából lehetséges nyersanyagok összetételének maghatározása. i) a lc nyersanyagok mikrobiológiai bonthatóságát javító egyes kémiai előkezelések ii) az előkezelt nyersanyagok enzimtermelésben történő hasznosítása iii)a fermentációs paraméterek hatása iv) az előállított enzim-keverékek jellemzőit és hidrolítikus hatékonysága v) az előkezelt lc.-k hidrolízisének kinetikája. | The three major subjects: 1. Membrane separations i) experimental and theoretical research of pervaporation and membrane filtrations, ii) new methodology for the modelling of pervap. of biner and terner mixtures, iii) pervap. based new hybrid technology to demonstrate the contribution to sustainable development, iv) prove of the wide range applicability of membr. filtrations, v) definition of succesful area of the two-step-membr. filtration, vi) modelling of membr. filtration. 2. Supercriticial extraction: i) several plants were extracted in a pilot unit using supercritical CO2, ii) employing a simple and a more detailed mathematical model the effects of the sample preparations, the extraction and separation conditions on parameters were examined. iii) the detailed model was improved, iv) the different products obtained with different extraction were compared. 3. Lignocellulose The potential of agricultural lignocellulosic byproducts for ethanol production in Hungary were assessed and composition analysis of feedstocks were carried out. In our work: i) chemical pretreatments for improved microbial degradability of lignocellulosic raw materials; ii) utilization of pretreated raw materials in enzyme production; iii) the effects of fermentation parameters; iv) the characteristic and hydrolytic performance of in-house produced enzyme mixtures; v) hydrolysis kinetic of pretreated lignocelluloses were investigated

Biomassza hasznosítás kémiai alapfolyamatainak tanulmányozása = Study of fundamental chemical processes of biomass utilization

(1) Biomassza anyagok széles skáláját vizsgáltuk termikus módszerekkel. A hőbomlásról, az égési folyamatokról, és az elgázosításról nyertünk ismereteket, valamint hozzájárultunk egyes biomassza-hasznosítási eljárások során lejátszódó folyamatok mélyebb megértéséhez. Olyan reakciókinetikai modelleket alkalmaztunk, ill. dolgoztunk ki, melyek nagyobb mérési sorozatokon, a kísérleti körülmények széles tartományában írják le a vizsgált termikus reakciókat, és tükrözték a vizsgált minták szerkezetének és felépítésének komplikált voltát. (2) Bioetanol gyártás tématerületen öt szubsztráton (gőzrobbantással előkezelt cukorcirok bagasz, kender, kender pozdorja és kontrollként két modell szubsztrát) vizsgáltuk a Tween 80 és a PEG 4000 adalékanyagok hatását különböző hőmérsékleteken. Kísérleteinkben kimutattuk, hogy ezen adalékanyagok hozzáadásával növelhető a szubsztrátok enzimes lebontásának hatékonysága. Cukorcirok alapú technológiák anyag- és energiamérlegének modellezésével igazoltuk, hogy a teljes termelési időszak alatt biztosítani lehet az üzem hőigényét a melléktermékek felhasználásával. (3) Bioszorbenseket állítottunk elő lignocellulóz típusú agro-hulladékokból (kipréselt repce pellet, keményítőmentes búzamag) kémiai módosításokkal, amelyek így alkalmasak voltak szervetlen illetve szerves anyagok (szennyezők) megkötésére. | (1) A wide range of biomass materials have been studied by thermal analysis and related methods. New knowledge was obtained on the thermal decomposition, combustion processes and gasification by CO2. The work contributed to a deeper understanding of the reactions taking place during various biomass utilization methods. Such reaction kinetic models were employed and developed that reflected the complexity of the studied materials and described larger series of experiments at various experimental conditions. (2) In the field of bioethanol production the effect of Tween 80 and PEG 4000 additives on five substrates (steam pretreated sweet sorghum bagasse, hemp, hemp hurds and two model substrates) was investigated at various temperatures. It was proven that these additives could increase the efficiency of enzymatic digestibility of these substrates. By modeling the mass and energy balances of sweet sorghum based technologies it was verified that the heat demand of the process can be covered during the whole production period by utilizing the by-products. (3) Biosorbents were prepared from lignocellulosic agricultural wastes (pressed rape seed pellet, starch free wheat seed) by chemical modifications. The products were suitable to bond organic and inorganic pollutants

Sweet sorghum juice and bagasse as a possible feedstock for bioethanol production

The aim of our study was to estimate the overall ethanol potential of a promising Hungarian sweet sorghum variety called ‘Monori Édes’ developed by Agroszemek Ltd. For ethanol production following parts of the plant can be utilized: the stem juice containing sucrose and the bagasse built up mainly from lignocellulose. As lignocellulosics have to be pretreated and hydrolyzed prior to fermentation, another purpose of our research was to apply weak alkaline pretreatment methods to enhance enzymatic digestibility of bagasse thus, to improve the ethanol yield. In our study the effect of two bases (NaOH and KOH) in two concentrations (1% and 2%) and at two temperatures (room temperature and 121 °C) was investigated on the efficiency of enzymatic hydrolysis. Every pretreatment type affected positively the hydrolysis efficiency but in different degrees. Best results were achieved with 2% NaOH at 121 °C. However highest ethanol conversion based on the glucan content of pretreated material was reached using 2% NaOH at room temperature. Summarizing the ethanol potentials of juice and bagasse an overall potential of about 8 300 L/ha was estimated

Techno-economic aspects of on site cellulase production

On-site cellulase production for lignocellulosic ethanol production based on SO 2-impregnated steam pretreatment followed by simultaneous saccharification and fermentation was investigated from a techno-economic aspect using Aspen Plus and Aspen Icarus softwares. The enzyme fermentation was assumed to operate batch-wise with a cycle time of 100 hours. The base case included sixteen 343 m3 aerated fermentors arranged in four lines operating according to a merry-go-round pattern. Besides the base case, three cases, with improved productivities, were investigated. The cost of the on-site enzyme production was estimated to range between 6.7-16.5 Eurocent/L ethanol. The cost of carbon source was not included in the total production cost, since the pretreated material was produced in the process

Possible substrates for Acetone-Butanol and Ethanol fermentation based on organic by-products

An assessment study was carried out on available biomass by-products in Hungary, and also several fruit juice wastes were evaluated for their accessibility to enzymatic hydrolysis. Among the fruit juice residue samples examined the best results were obtained with apple, peach, apricot and tomato. It can be shown that using intensive stirring, higher conversions can be reached. Highest conversion of 98 % - based on carbohydrate content - was obtained with frozen and thawed apple residues. ABE fermentation of apple pulp hydrolysate supplemented with glucose yielded high solvent concentrations up to 22.5 gil. For growth and solvent production supplementation by additional nutrients was not essential, however, this accelerated the process. Ethanol fermentation by baker's yeast was carried out on apple pulp hydrolysate supplemented with glucose. This also gave reasonable yields of about 90 % - based on glucose consumption