Chemistry and Biotransformation of Coffee By-Products to Biofuels

Coffee is one of the most consumed infusion drinks in the world and contains a large variety of chemical compounds responsible for their sensory qualities and their effects on the body. The beneficial effects of coffee have been attributed only to its most important and researched ingredient, caffeine, but now it is known that other components have also contributed to its properties. Due to a huge demand for this product, large amounts of waste are generated in the coffee industry, which are toxic and represent serious environmental problems. During the process of mechanical extraction of the coffee seed, residues generated are: pulp, mucilage and parchment, mainly. Coffee cherry consists of soluble carbohydrates, insoluble polysaccharides, lipids, nitrogenous components, caffeine and minerals. More than 50% is considered a waste; it no longer has any commercial application, knowing that its components could be exploited for the production of inputs and energy. This chapter presents the chemistry and biotransformation of by-products and coffee residues into second-generation biofuels, which can be bioethanol, biogas and biodiesel by fermentation, anaerobic digestion and trans-esterification, respectively. Biofuels offer greater energy security, lower emissions of greenhouse gases and particulate matter, rural development, reduced demand for oil, among others

Bioethanol Production from Coffee Mucilage

AbstractChiapas is one of the largest coffee-producing states in Mexico. In this industry, there are large quantities of waste, which are toxic and harmful to the environment. During the extraction process of coffee bean the waste generated are: pulp, mucilage and parchment. Recently, investigations have been done to utilize these residues for bioenergy generation. This paper provides an overview of coffee and one of its major industrial wastes. The objective of this research was the production of bioethanol from coffee mucilage at laboratory scale and extract and characterize the substrate used as raw material and establish a fermentation process for the production of bioethanol. Our results show the kinetics of fermentation of coffee mucilage as a substrate to yeast Saccharomyces cerevisiae. The cell density, concentration of ethanol, reducing sugar consumption, physico-chemical variables such as pH and temperature were analyzed. The Fermentation parameters such as growth rate, saturation constant and yields were estimated

Optimization of bioethanol production from coffee mucilage

"A response surface methodology with 2(k) full factorial design was applied to obtain optimum conditions for bioethanol production using coffee mucilage (CM) as the substrate and Saccharomyces cerevisiae NRRL Y-2034 as the inoculum. CM is an agro-industrial residue mainly composed of simple sugars; the product yield and productivity process were analyzed with respect to the fermentation, pH, temperature, and the initial sugar concentration. Employing the following predicted optimum operational conditions attained the highest bioethanol production: pH 5.1, temperature 32 degrees C, and initial sugar concentration 61.8 g/L. The estimated bioethanol production was 15.02 g/L, and the experimental production was 16.29 g/L +/- 0.39 g/L, with a bioethanol yield of 0.27 g/L and a productivity process of 0.34 g/Lh. Glycerol was the predominant byproduct of the fermentative metabolism of S. cerevisiae. The response surface methodology was successfully employed to optimize CM fermentation. In the fermentative processes with yeast, optimizing the conditions of the culture medium is needed to fully exploit the potential of the strains and maximize the production of bioethanol.

A Simple Method to Determine Bioethanol Production from Coffee Mucilage, Verified by HPLC

This paper proposes a method to determine bioethanol concentration that uses a pycnometer verified with a high performance liquid chromatography (HPLC) technique; it is a simple tool to determine the density of liquids for getting information about the ethanol concentration. The results showed that the sugar concentration affected the bioethanol concentration. A lower initial sugar concentration of 26.5 g/L generated higher yield of 45.3% sugar to bioethanol and a fractional or relative yield of 88.74%. Significance tests were used to compare the two experimental means, revealing that the pycnometer method and HPLC provide the same bioethanol concentration with joint variances of 2.269, 0.242, and 0.112 for 3 different tests with initial sugar concentrations of 26.486 g/L, 49.043 g/L, and 68.535 g/L, respectively. This study established and developed a methodology to determine bioethanol concentration from coffee mucilage by the proposed method

Drying Mango (Mangifera indica L.) with Solar Energy as a Pretreatment for Bioethanol Production

The drying kinetics of mango were examined as a first step of pretreatment for biofuels production. This method exploits the potential of the carbohydrate present in the raw material, where the concentration for fermentation was adjusted to 20 g/L of reducing sugars. Dehydration was carried out by natural convection using a solar dryer. The solar dryer employed was made of transparent acrylic, and it had an internal volume of 0.125 m3. The dehydration was performed through natural convection. The dehydration achieved 95.6% moisture removal in 28 h and reached maximum temperatures of 52 °C and 56 °C, corresponding to first and second phases, respectively. The minimum temperature reached was 21 °C. The rate of drying was evaluated during the first stage, between 0 to 4 hours, with radiation maxima of 991 and 1014 W/m2 for that day. At the peak of radiation the drying rate was 0.060 g H2O/ g dry mass/ min

Assessment of the Pretreatments and Bioconversion of Lignocellulosic Biomass Recovered from the Husk of the Cocoa Pod

The production of biofuels (biogas, ethanol, methanol, biodiesel, and solid fuels, etc.), beginning with cocoa pod husk (CPH), is a way for obtaining a final product from the use of the principal waste product of the cocoa industry. However, there are limitations to the bioconversion of the material due to its structural components (cellulose, hemicellulose, and lignin). Currently, CPH pretreatment methods are considered a good approach towards the improvement of both the degradation process and the production of biogas or ethanol. The present document aims to set out the different methods for pretreating lignocellulosic material, which are: physical (grinding and extrusion, among others); chemical (acids and alkaline); thermochemical (pyrolysis); ionic liquid (salts); and biological (microorganism) to improve biofuel production. The use of CPH as a substrate in bioconversion processes is a viable and promising option, despite the limitations of each pretreatment method

Assessment of the Pretreatments and Bioconversion of Lignocellulosic Biomass Recovered from the Husk of the Cocoa Pod

The production of biofuels (biogas, ethanol, methanol, biodiesel, and solid fuels, etc.), beginning with cocoa pod husk (CPH), is a way for obtaining a final product from the use of the principal waste product of the cocoa industry. However, there are limitations to the bioconversion of the material due to its structural components (cellulose, hemicellulose, and lignin). Currently, CPH pretreatment methods are considered a good approach towards the improvement of both the degradation process and the production of biogas or ethanol. The present document aims to set out the different methods for pretreating lignocellulosic material, which are: physical (grinding and extrusion, among others); chemical (acids and alkaline); thermochemical (pyrolysis); ionic liquid (salts); and biological (microorganism) to improve biofuel production. The use of CPH as a substrate in bioconversion processes is a viable and promising option, despite the limitations of each pretreatment method