Sustainable Development and Renewable Energy from Biomass in Peru-Overview of the Current Situation and Research With a Bench Scale Pyrolysis Reactor to Use Organic Waste for Energy Production

Peru is an interesting emerging market with a stable development and economic growth during the last years. This growth also brings new challenges for sustainable development. The rising energy demand and the increasingly high volumes of waste need sustainable solutions. Thus far, Peru has a big unused potential in the production of bioenergy, especially a big amount of unused biomass. With the construction of a small Flash Pyrolysis Reactor at the Pontificia Universidad Católica del Perú (PUCP), the research of the potential of different biomass feedstock for pyrolysis process has started. The first results and an overview of the current situation in Peru are presented in this paper.


Introduction
Peru is a megadiverse country in a constant economic growth that urgently demands careful sustainable development to protect and preserve its natural wealth.The territory is located in tropical and subtropical areas in South America.It would draw the conclusion that the climate should be warm and humid but, due to the presence of the Andes and a complex system of ocean currents and movements of air masses (South Pacific Anticyclone), a rich variety of climates is generated.Therefore, connected to its geological and ecological features, Peru becomes a megadiverse country.
According to Pulgar Vidal (1940), Peru has eight different natural regions (Chala, Yunga, Quechua, Suni, Puna, Janca, Rupa Rupa and Omagua) and one maritime region (Mar Peruano).However, the land could be broadly divided into three main regions: an arid desert region (Costa), mountains (Sierra) and a tropical forest (Selva) into which those, proposed by Pulgar Vidal, can be included.On the other hand, 84 different life zones, according to Holdridge, can be found in Peru, the country with the largest amount (Figure 1) in the world.Only in the Peruvian Amazon exists around 1700 varieties of birds as well as many species of mammals, fish and insects, being part of a great variety of unique fauna.Moreover, the Peruvian flora has the greatest variety of domesticated plants in the world; for example, there are over one thousand varieties of potatoes.National reserves in Peru are the richest sources of natural resources in the world (MINAM, 2013).
The area dedicated to agriculture is roughly 24% of the total land, and the forests cover 70% of the national territory, including the tropical rainforest (Khwaja, 2010).The economy of this developing country grew 6.92% in the year 2011 thanks to the mining sector as the most important income (Indexmundi, 2012).Around 91.5% of the Peruvians living in urban areas have access to public water systems compared to only 52.3% in rural areas.It is also a fact that not more than 72.5% of rural households have electric lighting in comparison to 98.8% of urban ones.Another alarming figure shows that 34.7% of the population suffers from calorie deficit (23.9% in Lima and up to 48.9% in rural areas), and 13.9% of the children under 5 years old suffers from chronic malnutrition.These numbers show that Peru has a state of food insecurity and, for this reason, it must be avoided that food production is affected by the bioenergy industry.It is important to emphasize that the lack of food and the rise of food prices are not only related to competition by liquid biofuels, these are also associated with low levels of income, inadequate use of food and other multiple factors (INEI, 2012)  Some projects in renewable energy field have been developed in the country, such as the use of sugar cane for the production of ethanol.Peru counts on 12 refineries with potential production capacity of 64 million liters per year.The high water demand of sugar cane and the water constraints in some regions of Peru raise the question whether it is more important to grow agrobiofuels instead of prioritizing crops for food production.For biodiesel production, oil palm (Elaeis guineensis) and jatropha (Jathropa curcas) are potential feedstock with some projects using jatropha at experimental stage to date.On the other hand, there is an installed area of more than 44 882 ha for oil palm, 38% of the total area in production, 34% in growth and the rest in nurseries (Khwaja, 2010).
Life cycle analyses of biofuel production in the Peruvian Amazon show that not all production ways make environmental sense.Nowadays, the fact that biofuel production is ecological or not in Peru strongly depends on the previous land use where the energy crops are planted.The most pessimistic scenarios are those where primary forests are destroyed to get farmland for energy crops (SVN, 2009).It can be shown from the carbon debt calculated for eight different scenarios.Oil palm and jatropha crops have positive environmental impacts on degraded forest land with values of -8.1 and -9.5 t CO 2 eq / ha, while biofuel production, in primary forests, incurs debts (the amount of years necessary using biodiesel in order to compensate for the carbon emissions caused by the land use change to produce biodiesel) of 40 and 140 years for oil palm and jatropha (SVN, 2009).
The most commonly bioenergy used in Peru is solid biofuel, as dung, firewood and charcoal, 10 -12% of total energy consumption is based on solid biomass.For the generation of electric power, the most important bioenergy resource is biogas generated by the anaerobic decomposition of plant and animal waste.Used residues include bagasse, rice husk, forestry waste, grain chaff, and remains from the poultry, beef cattle and pig farming.From January 2012 to September 2012, 114.9 GWh of electricity were produced by biogas, nearly twice compared to the production in the same period in the 2011 (OSINERGMIN, 2012).
The total offer of available biomass in Peru for the production of energy is 272 million metric tons according to WISDOM (Woodfuels Intergrated Supply/Demand Overview Mapping) analysis carried out by FAO (Felix & Rosell, 2010).This number includes 16 million tons of organic waste yearly available from agricultural and forest industries.The remaining 256 million tons represent the potential of woody biomass from the natural forests in Peru.The tropical forest zone has the biggest amount of available forest biomass, while the arid coastal region and the south of the Sierra have only a short supply of biomass.This heterogeneous distribution of resources is the result of geographical and climate variations that characterize the Peruvian territory.However, WISDOW analysis shows that many regions of the country have significant volumes of biomass that could potentially be used to provide local energy.For instance, the woody biomass and forest industry residues could be not only used for direct or indirect generation of local energy, but also transported over long distances as briquettes, coal, gas, etc. (Felix & Rosell, 2010).The production potential data for renewable energies, energy efficiency and co-generation in Peru, expressed in tons of oil equivalent (Toe), is shown in Table 1.2) Colors: green = favorable feature; purple = moderate feature; blue = unfavorable feature.

Flash Pyrolysis
Fast or flash pyrolysis occurs in a period of few seconds or less.Therefore, chemical reaction kinetics, heat and mass transfer processes as well as phase transition phenomena play important roles.The critical issue is to bring the reacting biomass particle to the optimum process temperature and minimize its exposure to the intermediate (lower) temperatures that favor formation of charcoal.It is possible to reach this goal by using small particles, for example, in the fluidized bed processes.Another way is to transfer heat very fast only to the particle surface that contacts the heat source, which is applied in ablative processes (Bridgewater, 2001).
In fast pyrolysis, the biomass decomposes to generate mostly vapors, aerosols and some charcoal.After cooling and condensation, a dark brown liquid is formed and its heating value is around half of that of conventional fuel oil.While it is related to the traditional pyrolysis processes in charcoal making, fast pyrolysis is an advanced process with carefully controlled parameters to give high yields of liquid products (Bridgwater, 2008).
The main product bio-oil is obtained in yields up to 75% wt on dry feed basis, (in the most developed processes) along with by-products such as charcoal and gas.Bio-oil is a liquid mixture of oxygenated compounds containing various functional chemical groups, such as carbonyl, carboxyl and phenolic components.The two by-products (gas and biochar) can be used to provide the process heat requirements, thus there are finally no other waste streams left than flue gas and ash (Pyne, 2012).
Based on the fact that there is a lot of unused potential biomass and a lack of appropriate local technology in Peru, a bench-scale Flash Pyrolysis Reactor was constructed at the Pontificia Universidad Católica del Perú (PUCP) to carry out first experiments with different feedstock.One of the goals was to use only materials and instruments available in Peru; therefore, nothing has to be imported.
For the first experiments, coffee ground was used.Peru is not only exporting special kinds of coffee all over the world but also the consumption within the country is rising.In general, coffee is the most widely traded tropical agricultural commodity in the world mainly used for beverages, with a production of 93.4 144 million bags (i.e. 4 750 000 in Peru) in the year 2012 (one bag weights 60 kilograms).Depending on coffee varieties, the oil amount varies from 11 to 20 wt% (ICO, 2012).With the increase of the coffee consumption, the volume of coffee ground is also growing.Normally, coffee ground is put into the household waste that goes mainly to landfills.In some cases, this feedstock is used as compost or deodorizer, but a big amount is unused and can be turned into renewable energy (Jin et al., 2012).

Results
After planning the small bench-scale reactor, the parts were constructed and assembled in one laboratory at PUCP.The reactor has a fluidized bed and can operate between 450 and 600°C.Specifications of the reactor are presented in Table 4.  Peru is a gifted land with a lot of potential to grow.Society and authorities not only should think in profit but also in sustainable development to protect its natural treasures and to provide social justice. Fig Fig