J. of Advancement in Engineering and Technology Volume 5 / Issue 1 ISSN: 2348-2931 1 JOURNAL OF ADVANCEMENT IN ENGINEERING AND TECHNOLOGY Journal homepage: http://scienceq.org/Journals/JAET.php Research Article Open Access A Novel Process for The Production of Potash from Plant Ash: Leaching Technique Ademola S. OLUFEMI 1* , Oluwafemi O. OLAYEBI 2 and Dandy E. MAKPAH 3 1 Department of Chemical/Petroleum Engineering, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. 2 Department of Chemical Engineering, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria. 3 Department of Agricultural/Environmental Engineering, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. *Corresponding author: Ademola S. OLUFEMI, Tel.: +2348033311087; E-mail: adestanford.olufemi@gmail.com Received: April 15, 2017, Accepted: May 22, 2017, Published: May 22, 2017. ABSTRACT The leaching process involved in the production of Potash from plant ash was investigated. Three samples viz palm inflorescence, sunflower stalks and corn stalks were selected, as the raw ash material for the leaching. Analysis of the solution resulting from the ash shows that sunflower stalks, palm inflorescence, corn stalks contain by weight 43.01 g and 28.19 g Potassium oxide (K 2 O) and a total solute content of 65.87 g, 63.61 g respectively. All other material that are not soluble in water are considered inert. Laboratory batch leaching experiments on the ash show that, the optimum leaching temperature for all the samples is 70 0 C for a particle size range of 295 nm to 45 nm. Extraction data on over-flow and under-flow at the optimum leaching temperature and size range gave the number of equilibrium stages to be three for a solvent to feed ratio 3.765, 3.44 and 2.81 for sunflower stalks, palm inflorescence and corn stalks ash respectively. A small scale model of a continuous counter-current leaching system was designed, constructed and tested. An overall stage efficiency of 22.4 % was obtained with the stated solvent to feed ratio. The efficiency of the system was however increased to 83 % by increasing the solvent to feed ratio to 12 times the former. Keywords: Counter-current-flow, Leaching, Over-flow, Plant-ash, Under-flow INTRODUCTION Agro-waste or plant biomass in Nigeria are mostly exposed to open-air burning with its associated environmental implications, but these wastes could be resourcefully managed if used for other viable industrial, agricultural, or domestic purposes, thereby decreasing the problem of environmental pollution and also creating wealth [1]. Plant biomass as a source of energy offers a cheap, environmentally friendly alternative to the conventional petroleum energy sources and these energy generated from biomass such as tree bark, wood residues, and other plant materials, produces a considerable amount of fly and bottom ashes. Managing waste ashes generated from plant is a major challenge, as land filling and open dumping are the main options in management of the waste ash. Cleared wood needed to be disposed of, and the easiest way to accomplish this was to burn any wood not needed for fuel or construction. Ashes from hardwood trees could be used to make lye, which could be used to make soap or boiled down to produce valuable potash. Exploration of ash-derived alkalis for domestic use is an ancient craft [2, 3] involving simple technology and chemistry [4]. The general principle in potash production from ashes involved leaching the ashes with water; the ‘leachate’ is then evaporated. The residue crude is the crude potash. The quality of the residue depends on the materials used, as well as procedure and equipment as reported by Babayemi et al. [4]. Materials for ashes in potash production such as wood [5, 6], plantain and banana peels [2], [7, 8], cocoa pod husk [9], palm bunch [10], and livestock dung [11] have low potash yield. Furthermore, some of those which give high potash yield are not available throughout the year. Plants contain alkali metals such as potassium, calcium, sodium and magnesium. These metals are present in form of various salts. When the plant matter is subjected to heat, burnt in presence of presence of air, the metals are oxidized to metal oxides. Carbon dioxide produced during burning of carbonaceous matter, combines with these alkali metallic oxide to produce alkali carbonate. Other products formed during burning, in presence of water vapour, are alkali bicarbonate potassium hydroxide as listed in Kumar [12]. These reactions can be expressed as: 2 2 2 3 ( ) ( ) 0 () XO s CO g XC s   (1) 2 3 2 2 3 0 ( ) ( ) ( ) 2 () XC s HO g CO g XHCO s    (2) 2 3 2 3 0 ( ) ( ) ( ) () XC s HO g XOH s XHCO s    (3) Where X denotes alkali metal The chemical reaction equilibrium constants for the above three reactions at 298 K are 2.00 × 10 60 , 2.07 and 0.33, respectively [9]. It is evident by looking at the order of magnitudes of chemical reaction equilibrium constants that reaction (1) predominates in the above reaction scheme. Olufemi et al. [13], refer to leaching as the extraction of a soluble constituent from a solid by means of different solvents: acids, bases, water and chelating agents. However, since acidic medium are advantageous for the dissolution of metals, acids are commonly used for the leaching of heavy metals. Sulphuric acid is the most common leaching agent because of its chemical properties and also its relatively low cost and the rate of leaching depends on the parameters used such as temperature, time, pH, particle size, concentration of lixiviate, slurry density and agitation speed [14, 15]. The process may be employed either for the production of concentrated solution of a valuable solid mineral, or order to free an insoluble solid, such as pigment, from a soluble material with which it is contaminated. The method used for the extraction will